Knowledge Management System Of Guangzhou Institute of Geochemistry，CAS
Cai, Yu-Xin1,2,3; Huang, Xiao-Long1,2; Xu, Yi -Gang1,2; Yu, Yang1,2; Li, Jie1 ; Yang, Fan1,2; Ge, Zhen-Min
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| Contribution of recycled oceanic crust to the extremely light molybdenum isotopic compositions of mid-ocean ridge basalts from the South China Sea | |
| Source Publication | CHEMICAL GEOLOGY
 |
| ISSN | 0009-2541 |
| 2024-02-20 | |
| Volume | 646Pages:13 |
| DOI | 10.1016/j.chemgeo.2023.121916 |
| Language | 英语 |
| WOS Research Area | Geochemistry & Geophysics |
| Abstract | The contribution of recycled oceanic crust to the mantle source of mid-ocean ridge basalts (MORBs) remains a subject of debate, as radiogenic isotopes alone yield ambiguous insights. Here, we present comprehensive data on whole-rock major element, trace element, and Mo-Nd-Hf isotopic compositions for MORB samples from International Ocean Discovery Program Expedition 349 sites U1431E and U1433B in the eastern (ESB) and southwestern (SWB) subbasins, respectively, of the South China Sea (SCS). The delta 98/95Mo values of the SCS MORBs exhibit a significant range (from -0.80%o to +0.05%o), in contrast to the restricted composition observed in MORBs (delta 98/95Mo = - 0.19%o +/- 0.01%o). The ESB MORBs display extremely light Mo isotopic compositions (delta 98/ 95Mo = - 0.80%o to - 0.24%o) with Nd-Hf isotopic compositions similar to those of Pacific MORB, whereas the SWB MORBs show higher delta 98/95Mo values (-0.44%o to +0.05%o) and depleted Nd-Hf isotopic compositions. The delta 98/95Mo values of the SCS MORBs are negatively correlated with Ce/Mo ratios and positively correlated with epsilon Hf values, suggesting the incorporation of dehydrated slab components into the source of the SCS MORBs. The subbasin-scale mantle heterogeneity in the SCS can be best explained by varying degrees of interaction between a mantle plume and stagnant slabs in the mantle transition zone, as suggested by mantle tomography. The rigid stagnant slab in the mantle transition zone beneath the SWB largely impeded the upwelling of the mantle plume, whereas the slab beneath the ESB was disrupted by the plume and subsequently transported into the upper mantle. This study, therefore, provides compelling evidence for the involvement of recycled oceanic slabs in generating MORB and the influence of an ascending mantle plume on seafloor spreading in a continental marginal sea. Mantle recycling processes in marginal sea basins exhibit distinct characteristics compared to those occurring in open oceans. |
| Keyword | Molybdenum isotopes Mid-ocean ridge basalts Recycled oceanic crust Mantle heterogeneity Plume-stagnant slab interaction South China Sea |
| WOS ID | WOS:001155829000001 |
| Indexed By | SCI |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.gig.ac.cn/handle/344008/76210 |
| Collection | 同位素地球化学国家重点实验室 |
| Corresponding Author | Huang, Xiao-Long |
| Affiliation | 1.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Ctr Excellence Deep Earth Sci, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 2.Southern Marine Sci & Engn Guangdong Lab, Guangzhou 511458, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China |
| Recommended Citation GB/T 7714 | Cai, Yu-Xin,Huang, Xiao-Long,Xu, Yi -Gang,et al. Contribution of recycled oceanic crust to the extremely light molybdenum isotopic compositions of mid-ocean ridge basalts from the South China Sea[J]. CHEMICAL GEOLOGY,2024,646:13. |
| APA | Cai, Yu-Xin.,Huang, Xiao-Long.,Xu, Yi -Gang.,Yu, Yang.,Li, Jie.,...&Ge, Zhen-Min.(2024).Contribution of recycled oceanic crust to the extremely light molybdenum isotopic compositions of mid-ocean ridge basalts from the South China Sea.CHEMICAL GEOLOGY,646,13. |
| MLA | Cai, Yu-Xin,et al."Contribution of recycled oceanic crust to the extremely light molybdenum isotopic compositions of mid-ocean ridge basalts from the South China Sea".CHEMICAL GEOLOGY 646(2024):13. |
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